DDR2 Vs DDR3 Vs DDR4 Vs DDR5 RAM: How are they different

Double data rate synchronous dynamic random-access memory or DDR SDRAM, if you want to keep it simple is a type of memory integrated circuits that are being used in computers nowadays.

RAM or random-access memory is a term most of us have come across during our days in school when we began to learn what a computer and its functions are. If you have ever bought a computer, you would have come at the very least read about the term on the specification list, if you have ever put together a computer, you probably know a little more about the different types of RAM.

RAM is a form of data storage available in computers which stores data and machine code that is currently being used by the system.

Hard drives can store a huge amount of data, that’s memory too, so why exactly do you need a random-access memory?

The files a program needs to perform a function might be located anywhere in the storage device that holds the information. The time the system takes to read or write memory will vary based on the location of that file within the memory. If you take a hard drive as your example, you will have to wait until the spinning platters to spin into the correct position despite the fact that they spin at thousands of rotations per minute. This creates a delay when the files are being read.

After the files are obtained from the drive, they are stored in the RAM. When files that are needed for that particular action needs to be accessed again and again, the files being available nearby reduces the delay that is present when the files are being accessed directly from the storage devices.

What is RAM Explained - GIZBOT

When a program is first loaded, all the relevant information it needs in order to function is stored in the RAM. And this data is deleted when it is shut down.

Double data rate synchronous dynamic random-access memory or DDR SDRAM facilitates higher transfer rates between the CPU and the memory, this is possible because of a stricter control it has over electrical data and the clock signals.

DDR SDRAMs have had multiple iterations over the years, the RAM slots available on motherboards are usually designed to receive a particular type of RAM. This is because the pin configuration for a DDR3 RAM is different from that of DDR2 or DDR4, this is why you need to make sure that the RAM you buy must be compatible with your computer.

This is because the specifications of each version [the bus clock (frequency of operation), voltage or transfer rate] are different.

The different iterations of DDR SDRAM that are available in the market and their differences are as follows:

1) DDR (2000)

Bus Clock (MHz): 100~200

Voltage (volts): 2.5~2.6

Transfer Rate (MT/s): 200~400

Prefetch (min burst): 2n

2) DDR2 (2003)

Bus Clock (MHz): 200~533.33

Voltage (volts): 1.8

Transfer Rate (MT/s): 400~1066.67

Prefetch (min burst): 4n

3) DDR3 (2007)

Bus Clock (MHz): 400~1066.67

Voltage (volts): 1.35~1.5

Transfer Rate (MT/s): 800~2133.33

Prefetch (min burst): 8n

4) DDR4 (2014)

Bus Clock (MHz): 1066.67~2133.33

Voltage (volts): 1.05~1.2

Transfer Rate (MT/s): 2133.33~4266.67

Prefetch (min burst): 8n

5) DDR5 (2019 estimated)

Intel held a presentation in 2016 which hinted at possible plans by JEDEC to release a 2016 DDR5 SDRAM specification with a possible release date of 2020. The JEDEC Solid State Technology Association is an independent semiconductor engineering trade organization and standardization body. Its members include some of the largest computer giants in the whole world.

In March 2017, a plan for a possible specification release in 2018. According to JEDEC’s Server Forum, a DDR5 SDRAM preview was announced and it was stated that it would be held on June 19, 2017. A DDR5 SDRAM workshop was announced from October 31 - November 1, 2017, was also announced.

The DDR5 is touted to consume far less power and double the memory bandwidth.